Bit for lifting tongs



Feb. 11, 1941. A, R ROWE 2,231,819

BIT FOR LIFTING TONGS Filed Aug. 18, 1959 4m 4 EEVi fE 0 Eon E, I

Patented Feb. 11, 1941 UNITED STATES PATENT OFFICE National TubeCompany,

Jersey a corporation of New Application August 18, 1939, Serial No.290,918

2 Claims.

This invention relates to bits for lifting tongs such as are employedfor handling metallic ingots, blooms, billets or slabs.

In the lifting of heavy objects, such as those referred to hereinabove,the lifting tongs are usually provided with bits having working ends ofpointed or convex shape. When a pointed or convex working end isemployed the article being lifted (for example, a highly heated ingot)may be scarred to a depth of /2 to A of an inch, and this scar appearsas a defect in the semi-finished product. In order to remove thisdefect, the object is conditioned by chipping or scarfing eithermanually or by a suitable machine. Any method by which the article isconditioned entails considerable expense.

In the case of a bit having a convex working point, the life of serviceis extremely short, as it must be redressed after several hours use.Such redressing is undesirable for the reason that the lifting tongs areout of service during the removal of the worn bits and the substitutiontherefor of suitably dressed bits.

In addition to the foregoing difiiculties bits having working ends ofpointed or convex shape due to their penetration into a highly heatedarticle (such as an ingot) pick up considerable heat and frequently mustbe cooled by dipping in water. This cooling is also objectionable, as inthe case of replacement, as it curtails the productive work of thecrane, charging machine, drawing machine or other apparatus employingthe bit.

It is among the objects of the present invention to provide bits forlifting tongs which not only eliminate scarring of the object beinglifted, but

which also have an enhanced life of service, thereby increasing theproductive work of the apparatus employing the same.

The invention, then, comprises the features hereinafter fully describedand as particularly pointed out in the claims, the following descriptionand the annexed drawing setting forth in detail the certain illustrativeembodiment of the invention, this being indicative of but one of thenumber of ways in which the principles of the invention may be employed.

In said annexed drawing:

Figure 1 is a perspective view of a conventional pair of tongs employingthe bit of the present invention;

Figure 2 is an end view of the working end of the bit; and

Figure 3 is a side elevation, partly in section, of the bit of Figure 2.

Referring more particularly to the drawing, the numeral 2 designates aconventional pair of lifting tongs which may be of any suitableconstruction and provided with the usual arms 3 having recesses orapertures 4 for the reception of the lifting bits.

Referring more particularly to Figure 3, the numeral 6 shows the bit ofthe present invention which comprises a metallic frusto-conical bodyhaving one of its ends 1 of reduced diameter and constructed to occupythe recesses or apertures 4 in the arms of the lifting tongs 2. Thefrustoconical body 6 is provided with a cylindrical bore 8 and carrieson its larger end an annular and continuous outwardly extending arcuatelip portion 9 formed on a single radius. This outwardly extendingarcuate lip portion 9 comprises the working end of the bit of theinvention, and due to its continuous arc, provides for reduced workingcontact with the article to be lifted. According to the prior art, theworking ends of bits of the class described are of pointed or convexshape, as mentioned hereinbefore. The device of the invention embodyingas it does the annular and continuous outwardly extending arcuate lipportion, provides a contact area of reduced width. Intermediate the bore8 and arcuate terminal portion 9 the frusto-conical body 6 is providedwith two angularly flared portions and H, the latter of which isnarrower and of lesser angularity.

Due to the fact that the hollow or recessed working end of the bit ofthe invention does not penetrate as far below the surface of the objectbeing lifted (such as a hot ingot), the bit picks up less heat and,consequently, does not have to be cooled as often by dipping in water.This, as before stated, adds to the life of the bit and also enhancesthe productive work of the apparatus employing the same.

While I have shown and described one specific embodiment of the presentinvention, it will be seen that I do not wish to be limited exactlythereto, since various modifications may be made without departing fromthe scope of the invention, as defined by the following claims.

I claim:

1. A bit for lifting tongs comprising a metallic body portion having aflared recess in its working end, said flared recess being connected tothe periphery of said bit by an annular and continuous outwardlyextending arcuate lip portion.

2. A bit for lifting tongs comprising a metallic body portion having aflared recess in its working end, said flared recess being connected tothe outer periphery of said bit by an annular and continuous outwardlyextending arcuate lip portion, the arc of which is based on a singleradius.

ANDREW REED ROWE.

